So as i understand it the 'use case' is for coercing 3rd party types into your own type hierarchy. Suppose you had: trait Foo { def bar(): Int } and 3

So as i understand it the 'use case' is for coercing 3rd party types into your own type hierarchy. Suppose you had: trait Foo { def bar(): Int } and 3rd party library had final class FooBar extends java.lang.Object { public int bar() { /** **/ } } you could simply define your methods to take in a: type BarAble = { def bar():Int } But obviously if the library class is not final, you can simply do: type ThirdPartyFoo = FooBar with Foo ThirdPartyFoo <: Foo